U2AF1 and acute myeloid leukemia: The definition of AML with myelodysplasia-related changes (AML-MRC) has been modified – mainly abandoning the morphologic criteria of dysplasia and newly incorporating molecular genetics (defining somatic mutations: ASXL1, BCOR, EZH2, SF3B1, SRSF2, STAG2, U2AF1, ZRSR2 based on previous studies [3, 4]).